1. Field
This invention relates to chemical vapor sterilizers. More particularly, this invention relates to methods and apparatus for the sterilization of items by vapors generated in a small sterilizer from injected liquid sterilants.
2. State of the Art
Chemical vapor sterilizers are well known. MDT Corporation of Torrance, Calif., markets such devices under the trademark "CHEMICLAVE.RTM.," for example. Sterilizers of this type are characterized by a chamber into which a prescribed quantity of liquid sterilant chemical is introduced. The liquid is heated in the chamber, thereby creating chemical vapor sterilant. Modern systems include a reservoir for holding sufficient liquid sterilant chemical for several sterilization cycles. Sterilant is delivered in liquid form from the reservoir through a transport system to the sterilizing chamber.
Dental and medical clinics, schools, research laboratories and similar facilities often require sterilization of a few items. For small loads, a sterilizer sized to fit on a tabletop or countertop is especially advantageous.
In current chemical sterilizers, the sterilant is typically injected into the sterilizing chamber at atmospheric pressure. As a result, pockets of air or much-diluted sterilant may result in less than adequate sterilization throughout the chamber. Lengthening the exposure time is generally not a satisfactory solution.
In addition, since most facilities do not wish to invest in systems to vent the sterilizer out of doors, gases and vapors containing residual chemical sterilant components may be discharged directly into the interior of a room. The possibility exists for unacceptable levels of chemical irritants, e.g. formaldehyde, to accumulate in the room over a prolonged period.
The control systems, including the valving system, of current chemical sterilizers may also provide opportunities for undetected operator errors.
The need exists for a small chemical sterilizer which consistently provides the desired sterilization within a short turnaround time, is simple to operate, and prevents or minimizes the escape of sterilant components into the atmosphere.